Many systems have been proposed heretofore for verifying identifications by analyzing an invariant physical characteristic of a person such as his fingerprint. Some of these techniques involve an examination of the image of the fingerprint by irradiating the same with light. The image formation can be filtered in terms of frequencies and compared with similar stored information in a spatial domain.
In other systems, a light diffraction pattern is generated from a person's fingerprint and an electrical function of the detected diffraction pattern is derived. The technique for deriving the electrical function of the diffraction pattern involves a mechanical scanning of the diffraction pattern so that electrical information is derived in series; that is, the electrical function is continuously generated over a period of time corresponding to the time necessary to complete the scanning of the pattern. Again this electrical function can be compared with a stored electrical function to determine if a proper correlation exists and thereby verify the identity of a person.
The reliability and accuracy of any specific identification or verification carried out by the aforementioned prior art arrangements depends on the total amount of information that can be derived for comparison with the stored information. In other words, the derived electrical function from an image or a diffraction pattern of a person's fingerprint is more reliable the more data there is contained in the electrical function.